Premises and Equipment - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Operating lease term	5 years
Discount rate	1.25%
Lease expense	$ 34,000	$ 0	$ 0
Belfast, Maine Branch
Property, Plant and Equipment [Line Items]
Operating lease term	21 years
Discount rate		1.875%